权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Two-dimensional neural processing of auditory information in mammalian auditory cortex

哺乳动物听觉皮层听觉信息的二维神经处理

基本信息

批准号：
03452165
负责人：
HORIKAWA Junsei
金额：
$ 4.35万
依托单位：
Tokyo Medical and Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

We studied 2-dimensional activities of auditory cortex in guinea pigs and rats using a 4x 4 channel microelectrode-array technique and an optical recording method with a 12 x 12 channel photodiode array. The aim of this study was to examine how the auditory cortex processes auditory information in a two-dimensional way along the cortex. The animals were anesthetized with Nembutal (30 mg/kg) and neuroleptanalgesia (droperidole 16.7 mg/kg/h and pentazocine 5 mg/kg/h). For optical recording, the auditory cortex was stained with a voltage sensitive dye RH795 (styryl dye, Molecular Probes, Inc.). Color-coded spatiotemporal response patterns were displayd on a monitor screen. Sound stimuli used were pure tone bursts, frequency modulated (FM) sounds and vocalizations of the animals. They were presented to the ear contralateral to the recording side.Tonotopical representation of the auditory cortex in guinea pigs and rats was confirmed by the present study using these 2-dimensional recording s … More ystems. We found newly that this tonotopical representation through the functional organization of the cortex is only transient and it varies with time. The neural activity in the guinea pig auditory cortex usually initiates ventrally and it propagates toward dorsally along the cortical surface. The moving direction is parallel to the isofrequency band. For FM sound stimulation, the neural activity propagates obliquely across the isofrequency bands. When a direction of FM sweep is reversed, the direction of propagation is reversed in the frequency axis, but not in the dorsocaudal axis. By applying bicuculline, a GABA_A antagonist, to the auditory cortex, we found strong GABAergic inhibition between isofrequency bands. However, cross-correlation analysis between action potentials of neuron pairs recorded by the microelectrode-array revealed that neurons located in about 0.5 mm separation along the cortical surface rarely showed neural correlations. Vocalization-specific responses were not found in the present study. These results indicate that parameters of sounds are represented in a 2-dimensional way along the auditory cortex, and that the auditory information was transformed into places within the auditory cortex. Less

我们使用 4x 4 通道微电极阵列技术和使用 12 x 12 通道光电二极管阵列的光学记录方法研究了豚鼠和大鼠听觉皮层的二维活动。本研究的目的是检查听觉皮层如何沿着皮层以二维方式处理听觉信息。用戊巴比妥（30mg/kg）和安定镇痛剂（氟哌啶醇16.7mg/kg/h和喷他佐辛5mg/kg/h）麻醉动物。对于光学记录，听觉皮层用电压敏感染料 RH795（苯乙烯基染料，Molecular Probes, Inc.）染色。颜色编码的时空响应模式显示在监视器屏幕上。使用的声音刺激是纯音爆发、调频（FM）声音和动物的发声。它们被呈现给录音侧对侧的耳朵。本研究使用这些二维录音系统证实了豚鼠和大鼠听觉皮层的音调表征。我们新发现，这种通过皮层功能组织的音调表征只是暂时的，并且随时间而变化。豚鼠听觉皮层的神经活动通常从腹侧开始，并沿着皮层表面向背侧传播。移动方向平行于等频带。对于 FM 声音刺激，神经活动在等频带上倾斜传播。当 FM 扫描方向反转时，传播方向在频率轴上反转，但在背尾轴上不反转。通过将 GABA_A 拮抗剂荷包牡丹碱应用于听觉皮层，我们发现等频带之间有很强的 GABA 能抑制作用。然而，微电极阵列记录的神经元对动作电位之间的互相关分析表明，沿皮质表面间隔约 0.5 mm 的神经元很少表现出神经相关性。本研究中未发现发声特异性反应。这些结果表明，声音参数沿着听觉皮层以二维方式表示，并且听觉信息被转换到听觉皮层内的位置。较少的